Here's something that you might not know about the humble cactus: it has tiny cracks in its skin, which open up at night when conditions tend to be more humid. This allows it to take up moisture. During the day, those cracks close up, keeping the moisture inside. Now, scientists have applied that same principle to a membrane which could make fuel cells a more viable option for powering vehicles.
Proton exchange membrane fuel cells need to be kept hydrated in order to work. This means that when they're used in cars, they have to be installed along with a radiator, water reservoir and humidifier. These items take up space, plus they consume power.
In order to do away with all that extra "stuff," researchers from Australia's CSIRO (Commonwealth Scientific and Industrial Research Organisation) and Hanyang University in Korea decided to copy the cactus.
The membrane that they created surrounds the fuel cell. When water is generated via a chemical reaction, it is absorbed by the cell, passing through tiny pores in the membrane as it does so. Once conditions get drier, the pores close up, keeping the water from evaporating. In particularly hot conditions, the technology can increase the efficiency of fuel cells by as much as a factor of four.
"At the moment, one of the main barriers to the uptake of fuel cell electric vehicles is water management and heat management in fuel cell systems," says Hanyang's Prof. Young Moo Lee, who led the project. "This research addresses this hurdle, bringing us a step closer to fuel cell electric vehicles being more widely available."